1. Field of the Invention
This invention relates to a working vehicle having an engine disposed in a forward position of a vehicle body, and a propelling transmission disposed in a rearward position of the vehicle body for receiving engine output transmitted through a hydraulic stepless transmission.
2. Description of the Related Art
As an example of conventional working vehicles as noted above, an agricultural tractor is disclosed in Japanese Patent Laying-Open Publication H7-329587. This tractor has a body frame formed of an engine, a front transmission integrated with the rear of the engine, a transmission frame coupled at a forward end thereof to the front transmission, and a rear transmission coupled to the rear end of the transmission frame. A hydraulic stepless transmission is mounted in the transmission frame for changing speed of engine output and transmitting it to the rear transmission.
The above prior art vehicle has a complicated construction since the body frame and transmissions must be formed separately. This vehicle has a further disadvantage that an upper portion of the vehicle body is at a high level above the ground while the bottom of the vehicle body is at a low level above the ground.
Other conventional examples of working vehicles are disclosed in U.S. patent Ser. No. 4,997,760 and Japanese Patent Laying-Open Publication S64-16436. In these working vehicles, a stepless transmission is operable by a change speed pedal. The driver may operate the stepless transmission easily with a foot to control the running speed of the vehicle. In these working vehicles, the change speed pedal and a control part of the transmission are relatively remote from each other longitudinally of the vehicle body. Thus, where the change speed pedal and transmission are connected to each other through an interlocking mechanism (pivotal links and rods, etc.), friction and flexibility of connecting parts in the interlocking mechanism result in increased operational resistance and play, which impair response and tend to worsen operability of the vehicle. Besides, the change speed pedal is located at a low level for the level at which the transmission is disposed, and is low relative to the driver's seat. Consequently, when the driver depresses the change speed pedal, an excessive force acts on the driver's foot at a relatively early stage of operation. This results in inconveniences of a reduced shifting range and the like which tend to worsen operability.
As a further example of conventional working vehicles, a tractor is disclosed in Japanese Patent Laying-Open Publication H7-32897. In this tractor, a change speed pedal is supported by a support bracket fixed to a body frame. The change speed pedal is coupled to a trunnion (control part) of a stepless transmission through a link and so on. Running speed may be changed by controlling the stepless transmission with the change speed pedal. In many tractors, the driving deck is supported by the body frame through rubber cushions. In the tractors having a change speed pedal supported by the body frame as in this conventional tractor, the driver's foot attempting to operate the change speed pedal may inadvertently deviate therefrom when a relative displacement due to running vibration or the like occurs between the driving deck above the rubber cushions and the body frame below the rubber cushions.